.bg-container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100vh;
  padding: 20px;
  background: #4096ff;
  box-sizing: border-box;
}

.app-container {
  display: flex;
  justify-content: center;
  align-items: center;
  height: 100%;
  width: 100%;
  border-radius: 5%;
  background: #fff
}

.app-container > div{
  /* 防止子元素宽度溢出 */
  width: 100%;
}
